<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <style>
    .button{
      width: 100px;
      height: 25px;
      transform: skewX(45deg);
    }
    .button > div{
      transform: skewX(-45deg);
    }

    .diamond {
    	width: 250px;
    	height: 250px;
    	transform: rotate(45deg);
    	overflow: hidden;
    	margin: 100px;
    }

    .diamond img {
    	max-width: 100%;
    	transform: rotate(-45deg) scale(1.42);
    	z-index: -1;
    	position: relative;
    }
  </style>
</head>
<body>
  <button class="button"><div>btn1</div></button>
  <div class="diamond">
    <img src="../adamcatlace.jpg" alt="">
  </div>
</body>
</html>
